Depression is a common and serious condition affecting more than 340 million people worldwide. Many people seek medical care and are prescribed medication for depression, however, between 10 and 30 percent of patients continue to have symptoms of depression while taking medication, which is a condition known as treatment resistant depression. TRD is typically defined as having continuing symptoms of depression after two or more medications have been tried, and patients can be either fully or partially treatment resistant. When traditional medications for depression do not produce the desired results, alternative medications may be used, either alone or as an adjunct medication, to combat TRD.
Lithium
Lithium works by enhancing serotonin transmission and is the most commonly used add-on medication for depression. Extensive research has been conducted on the use of Lithium and research conducted by the department of psychiatry at McGill University in Montreal, Canada, showed that 30 to 65 percent of patients responded well to Lithium treatment, in some cases within only 48 hours, though this is not typical.
Side effects from lithium use include hand tremors, weight gain, increased thirst and urine production, and mild cognitive impairment. It is common to strive to use the lowest possible dose of lithium, as higher blood serum levels often result in more side effects without producing higher rates of effectiveness. The ideal blood serum level for lithium is between 0.4 and 0.8 mEq/mmol per L, according to American Family Physician, a publication of the American Academy of Family Physicians.
Symbyax
Symbyax, produced by Eli Lilly and Co., is a combination of two medications, olanzapine and fluoxetine HCl capsules, and has been approved by the U.S. Food and Drug Administration for the treatment of treatment resistant depression. The FDA indicates that three clinical studies have shown Symbyax to be more effective in treating treatment resistant depression than either a placebo or fluoxetine alone. Common side effects include drowsiness, blurred vision, constipation or diarrhea, dry mouth, sore throat, increased appetite, and weight gain.
Buspirone
Buspirone is under the brand name BuSpar and is prescribed in either 5mg, 10mg or 15mg tablets. Dr. Roger Cadieux, of Pennsylvania State University College of Medicine, explains that though buspirone has no specific or intrinsic antidepressant effects, it has been shown to decrease the nonspecific symptoms of depression. According to Cadieux, a number of studies have shown dosages of 15mg to 30mg daily for three months improved depression symptoms in up to two-thirds of patients. Minor side effects were reported in clinical trials, including lightheadedness and nausea; however, for most patients the side effects were temporary.
